Solar energy is the most promising source of renewable, clean energy to replace the current reliance on fossil fuels. To make solar energy viable, inexpensive materials that efficiently convert solar radiation into electricity must be developed. The bulk photovoltaic effect (BPVE) has long been observed in bulk polar materials, especially ferroelectrics. Despite intense initial interest in these materials, early explorations revealed low energy conversion efficiency, in part due to the high band gaps of most known ferroelectrics.
Thus, there is a need for novel materials exhibiting the bulk photovoltaic effect with low band gaps. The invention is directed to these and other important needs.